# US 10,503,179 B2 · Flow rate control apparatus and program recording medium having recorded therein program for flow rate control apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,503,179 B2 - Document ID: US10503179B2 - Status: Granted - Kind: B2 - Application number: 15/832,282 - Filed: 2017-12-05 - Published: 2018-06-21 - Granted: 2019-12-10 - Earliest claimed: 2016-12-15 - Assignees: HORIBA STEC, Co., Ltd. - Applicants: HORIBA STEC, Co., Ltd. - Inventors: Shigeyuki Hayashi; Kentaro Nagai; Masao Yamaguchi - Web page: https://patentgrep.com/patent/US10503179B2 ## CPC - G05D 7/0635: {by action on throttling means (G05D7/0688, G05D7/0694 take precedence)} - F16K 37/005: {for measuring fluid parameters (F16K37/0033 takes precedence)} - G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES - F16K: VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING {(devices for emptying and evacuating the excess liquid in valves or conduits F16L55/07)} ## Abstract A flow rate control apparatus is provided which enables high speed response particularly in a transient response state, such as when a target flow rate falls. The flow rate control apparatus includes: a valve provided with a position sensor to measure an opening degree and disposed in a flow channel; a flow rate sensor disposed upstream of the valve and provided with a restrictor; a first pressure sensor disposed downstream of the restrictor and disposed upstream of the valve; a second pressure sensor disposed downstream of the valve; a storage section to store a characteristic map indicating a relationship between at least the opening degree of the valve, a differential pressure before and after the valve, and a flow rate of a fluid passing through the flow channel; and a valve control section to control the valve so that the flow rate reaches an accepted target flow rate. ## Claims ### Claim 1 A flow rate control apparatus comprising: a valve provided with a position sensor to measure an opening degree and disposed in a flow channel that permits passage of a fluid; a flow rate sensor disposed upstream of the valve and provided with a fluid resistance element, the flow rate sensor being designed to output a first flow rate; a first pressure sensor disposed downstream of the fluid resistance element and disposed upstream of the valve, wherein the first pressure sensor is configured to measure a first pressure of the fluid between the fluid resistance element and the valve; a control circuit configured to: store a characteristic map indicating a relationship between at least an opening degree of the valve, a differential pressure before and after the valve, and a flow rate of a fluid passing through the flow channel; calculate a second flow rate from the characteristic map on a basis of a measured opening degree measured by the position sensor and the first pressure measured by the first pressure sensor; determine whether a flow rate of a fluid passing through the flow channel is in a stable state or a transient state; and control the valve so that a flow rate of a fluid passing through the flow channel reaches a target flow rate, wherein, when the flow rate is determined to be in a stable state, control an opening degree of the valve on a basis of the target flow rate and the first flow rate outputted from the flow rate sensor, and wherein, when the flow rate is determined to be in a transient state, control an opening degree of the valve on a basis of the target flow rate and a second flow rate. ### Claim 2 (depends on 1) The flow rate control apparatus according to claim 1, wherein the control circuit is further configured to update the characteristic map when the flow rate is determined to be in a stable state, on a basis of the first flow rate being measured by the flow rate sensor, the first pressure being measured by the first pressure sensor, and a measured opening degree being measured by the position sensor. ### Claim 3 (depends on 1) The flow rate control apparatus according to claim 1, wherein the characteristic map indicates a relationship between a temperature of the fluid, an opening degree of the valve, a differential pressure before and after the valve, and a flow rate of a fluid passing through the flow channel. ### Claim 4 (depends on 1) The flow rate control apparatus according to claim 1, further comprising a second pressure sensor disposed downstream of the valve, wherein the control circuit is further configured to calculate a second flow rate from the characteristic map on a basis of a measured opening degree being measured by the position sensor, the first pressure being measured by the first pressure sensor, and a second pressure being measured by the second pressure sensor. ### Claim 5 (depends on 4) The flow rate control apparatus according to claim 4, wherein, when the flow rate is determined to be in a stable state, the control circuit is further configured to update the characteristic map on a basis of the first flow rate being measured by the flow rate sensor, the first pressure being measured by the first pressure sensor, a second pressure being measured by the second pressure sensor, and a measured opening degree being measured by the position sensor. ### Claim 6 (depends on 1) The flow rate control apparatus according to claim 1, wherein the flow rate sensor further comprises an upstream-side pressure sensor disposed upstream of the fluid resistance element, wherein the control circuit is further configured to calculate the first flow rate on a basis of an upstream-side pressure measured by the upstream-side pressure sensor and the first pressure measured by the first pressure sensor. ### Claim 7 (depends on 1) The flow rate control apparatus according to claim 1, wherein the flow rate sensor further comprises: a branch pipe branched from an upstream side of the fluid resistance element and joined to a downstream side of the fluid resistance element; and a pair of winding resistances disposed in the branch pipe, wherein the control circuit is further configured to calculate the first flow rate on a basis of output of the pair of winding resistances. ### Claim 8 A flow rate control apparatus comprising: a valve provided with a position sensor to measure an opening degree and disposed in a flow channel that permits passage of a fluid; a flow rate sensor disposed downstream of the valve and provided with a fluid resistance element, the flow rate sensor being designed to output a first flow rate; a first pressure sensor disposed downstream of the fluid resistance element and disposed upstream of the valve, wherein the first pressure sensor is configured to measure a first pressure of the fluid between the fluid resistance element and the valve; a control circuit configured to: store a characteristic map indicating a relationship between at least an opening degree of the valve, a differential pressure before and after the valve, and a flow rate of a fluid passing through the flow channel; calculate a second flow rate from the characteristic map on a basis of a measured opening degree measured by the position sensor and the first pressure being measured by the first pressure sensor; determine whether a flow rate of the fluid passing through the flow channel is in a stable state or a transient state; and control the valve so that the flow rate of the fluid passing through the flow channel reaches a target flow rate, wherein, when the flow rate is determined to be in a stable state, control an opening degree of the valve on a basis of the target flow rate and the first flow rate outputted from the flow rate sensor, wherein, when the flow rate is determined to be in a transient state, control an opening degree of the valve on a basis of the target flow rate and a second flow rate, the flow rate sensor further comprising: a high resistance flow channel provided with the fluid resistance element; a low resistance flow channel disposed in parallel to the high resistance flow channel and joined through a terminal end to the high resistance flow channel; and a switching valve to perform switching between the high resistance flow channel and the low resistance flow channel so that a fluid passes through one of the flow channels, wherein, when the flow rate is determined to be in a transient state, the switching valve is designed to permit passage of a fluid into the low resistance flow channel. ### Claim 9 A flow rate control apparatus comprising: a valve provided with a position sensor to measure an opening degree and disposed in a flow channel that permits passage of a fluid; a flow rate sensor disposed upstream of the valve and provided with a fluid resistance element; a first pressure sensor disposed downstream of the fluid resistance element and disposed upstream of the valve, wherein the first pressure sensor is configured to measure a first pressure of the fluid between the fluid resistance element and the valve; a second pressure sensor disposed downstream of the valve; and a control circuit configured to: store a characteristic map indicating a relationship between at least an opening degree of the valve, a differential pressure before and after the valve, and a flow rate of a fluid passing through the flow channel; and control an opening degree of the valve so that a flow rate of a fluid passing through the flow channel reaches a target flow rate, wherein, when a target flow rate is in a transient state, determine a target opening degree from the characteristic map on a basis of the target flow rate being accepted and the first pressure measured by the first pressure sensor, and control an opening degree of the valve so that a measured opening degree measured by the position sensor reaches the target opening degree. ### Claim 10 A memory storage device having recorded therein a program for a flow rate control apparatus comprising a valve provided with a position sensor to measure an opening degree and disposed in a flow channel that permits passage of a fluid, a flow rate sensor disposed upstream of the valve and provided with a fluid resistance element, the flow rate sensor being designed to output a first flow rate, and a first pressure sensor disposed downstream of the fluid resistance element and disposed upstream of the valve, wherein the first pressure sensor is configured to measure a first pressure of the fluid between the fluid resistance element and the valve, the program recording medium causing a computer to: store a characteristic map indicating a relationship between at least an opening degree of the valve, a differential pressure before and after the valve, and a flow rate of a fluid passing through the flow channel; calculate a second flow rate from the characteristic map on a basis of a measured opening degree measured by the position sensor and the first pressure measured by the first pressure sensor; determine whether a flow rate of a fluid passing through the flow channel is in a stable state or a transient state; and control the valve so that a flow rate of the fluid passing through the flow channel reaches a target flow rate, wherein, when the flow rate is determined to be in a stable state, control an opening degree of the valve on a basis of the target flow rate and the first flow rate outputted from the flow rate sensor, and wherein, when the flow rate is determined to be in a transient state, control an opening degree of the valve on a basis of the target flow rate and a second flow rate on a basis of a measured opening degree measured by the position sensor.